The Mind's Eye is held by an ogre mage, east of here and deep within the Mosh'Ogg ogre mound. His name is Mai'Zoth. I know him from when the Darkspears dwelt in Stranglethorn - he is vicious, and his magic is strong.
And if he has the Mind's Eye, then his magic will be stronger still.
You must face Mai'Zoth and wrest from him the Mind's Eye. It is a perilous task, but it is the only hope we have of saving Yenniku.
You retrieved the eye! Your might is the stuff of legends, <name>!
And in getting the Eye, you must have defeated Mai'Zoth and sent him to the Nether. That is why the spirits would not mention him before.
It is good that he is gone from the world of flesh and bone, but now that he is in the realm of spirits...I fear he will begin a new reign.
But that is a worry for another time. Now, I must perform a ritual to bend the Mind's Eye to our needs...